Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections affected by stress

In a new longitudinal study appearing in Biological Psychiatry, published by Elsevier, researchers identified new infections in children and adolescents with Tourette syndrome (TS) and/or OCD, and compared them with healthy control subjects. They also measured the participants' levels of emotional stress. Prior research has shown that stress is an important factor in developing depression, and that individuals with TS or OCD tend to be particularly sensitive to stress.

They then used this data to examine the power of the infections and measures of psychosocial stress to predict future tic, obsessive-compulsive, and depressive symptom severity.

Dr. James Leckman, senior author of this project, explains their findings: "We found that periods of tic and OC symptom worsening were independently associated with antecedent newly diagnosed strep infections as well as higher levels of antecedent psychosocial stress. When we looked at just the PANDAS, we also found similar results."

In other words, stress may aggravate the impact of prior streptococcal infection in promoting symptoms of TS and OCD. There was no impact of prior streptococcal infections on depressive symptoms.

PANDAS remain a controversial topic for many Tourette's experts. For example, another recently completed intensive longitudinal study that tracked a larger number of PANDAS cases found little evidence to support a link between newly diagnosed strep infections and a marked worsening of tic or obsessive-compulsive symptoms.

PANDAS is also frequently diagnosed in the community without the application of all the published diagnostic criteria. This has resulted in unwarranted use of antibiotic treatment for TS or OCD when there is no evidence of a recent strep infection.

However, some version of PANDAS likely does exist. The typical PANDAS case appears to have an abrupt sudden onset of separation anxiety and obsessive-compulsive symptoms, a loss of writing skills, and sleep problems. Tics are often present, but they can also confuse the picture, especially if they had been present in some form prior to PANDAS onset.

It is important to note that the number of PANDAS cases in this study was too small to allow firm conclusions, but it does indicate how important psychosocial stress is in TS and OCD, as well as depression.